Machines for manufacturing hollow objects in thermoplastic materials

Abstract

A mandrel assembly for use in shaping and injection molds, the assembly includes a support having compressed air channels, and a mandrel extending upwardly from the support and having spaced-apart ramps extending radially outwardly therefrom. A cap slidingly fits over the mandrel and has a free end positioned over the compressed air channels of the support. The cap also has an inner groove loosely receiving the ramps of the mandrel such that the cap is secured to the mandrel yet is able to slide up and down on the mandrel such that the free end of the cap will cover and uncover the channels. According to another embodiment of the present invention, the mandrel has an outer groove, and a plurality of balls are received in the outer groove. The cap has an inner groove corresponding to the outer groove that loosely receives the balls such that the cap is secured to the mandrel yet is able to slide up and down on the mandrel such that the free end of the cap will cover and uncover the channels.

Dependencies are inferred from the claim text.